Alloy plate coated material and method of producing alloy plate coated material

ABSTRACT

Provided is an alloy plate coated material including a base material, and an alloy plate layer which is formed on the base material to constitute an outermost layer and is formed from a M1-M2-M3 alloy (provided that M1 is at least one element selected from Ni, Fe, Co, Cu, Zn and Sn; M2 is at least one element selected from Pd, Re, Pt, Rh, Ag and Ru; and M3 is at least one element selected from P and B), in which the alloy plate layer has a molar ratio of M1 to M2 (M1/M2) of 0.005 to 0.5.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates to an alloy plate coated material and amethod of producing an alloy plate coated material.

2. Description of the Related Art

Conventionally, as an electrical contact material used in connectors,switches, printed wiring boards and the like, a member having an alloyplate layer for enhancing corrosion resistance and electricalconductivity formed on the surface of a base material, has been used.

Regarding such a member having an alloy plate layer formed on thesurface of a base material, for example, Patent Document 1 (JapanesePatent Application Publication No. 2011-249247) discloses an alloy platecoated material configured such that an amorphous alloy plate layerformed from an amorphous alloy composed of predetermined elements isformed on a base material.

SUMMARY OF THE INVENTION

However, in the alloy plate coated material disclosed in Patent Document1 described above, there is a problem that the amorphous alloy platelayer composed of predetermined elements has excellent corrosionresistance but has insufficient electrical conductivity, so thatsatisfactory characteristics as an electrical contact material are notobtained.

The invention was reported under such circumstances, and it is an objectto provide an alloy plate coated material having excellent electricalconductivity in addition to corrosion resistance.

The present inventors conducted a thorough investigation so as toachieve the object described above, and as a result, the presentinventors found that in regard to an alloy plate layer formed as anoutermost layer on a base material, when an alloy plate layer in whichthe mixing ratio of the particular elements that constitute the alloy isin a predetermined range is used, the object described above can beachieved. Thus, the present inventors completed the invention.

Furthermore, the present inventors found that in a case in which themixing ratio of the particular elements that constitute the alloy is notin the predetermined range, corrosion resistance of the amorphous alloyplate layer is deteriorated. For example, in a case in which the alloyplate layer is used for a long time period in a corrosive atmosphere asin the case of a fuel cell member, there is a risk that metals that haveliquated over time may adversely affect the power generationcharacteristics of the fuel cell. Therefore, there is a demand for aplate coated material having both corrosion resistance and electricalconductivity.

That is, according to the invention, there is provided an alloy platecoated material including a base material; and an alloy plate layerwhich is formed on the base material to constitute an outermost layerand is formed from a M1-M2-M3 alloy (provided that M1 is at least oneelement selected from Ni, Fe, Co, Cu, Zn and Sn; M2 is at least oneelement selected from Pd, Re, Pt, Rh, Ag and Ru; and M3 is at least oneelement selected from P and B), in which the alloy plate layer is aplated layer having a molar ratio of M1 to M2 (M1/M2) of 0.005 to 0.5.

In regard to the alloy plate coated material of the invention, it ispreferable that the alloy plate layer has a glass transition point.

In regard to the alloy plate coated material of the invention, it ispreferable that the alloy plate layer is amorphous-like.

In regard to the alloy plate coated material of the invention, it ispreferable that when the alloy plate layer is analyzed by a grazingincidence X-ray diffraction method using an X-ray diffractometer, thediffraction profile has a shape which has no sharp peaks originatingfrom crystals containing at least one element selected from among M1, M2and M3, and/or a shape which has a halo originating from an amorphousstructure.

Furthermore, according to the invention, there is provided a method ofproducing an alloy plate coated material, the method including a step offorming, by electroless plating, an alloy plate layer formed from aM1-M2-M3 alloy (provided that M1 is at least one element selected fromNi, Fe, Co, Cu, Zn and Sn; M2 is at least one element selected from Pd,Re, Pt, Rh, Ag and Ru; and M3 is at least one element selected from Pand B) on a base material so as to constitute an outermost layer, inwhich the alloy plate layer has a molar ratio of M1 to M2 (M1/M2) is0.005 to 0.5.

Effect of Invention

According to the invention, an alloy plate coated material havingexcellent electrical conductivity in addition to corrosion resistancecan be provided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating the configuration of an alloy platecoated material 100 related to the present embodiment;

FIG. 2A is a diagram illustrating an example of the diffraction profileobtained by analyzing the crystal structure of Pd by a grazing incidenceX-ray diffraction method using an X-ray diffractometer;

FIG. 2B is a diagram illustrating an example of the diffraction profileobtained by analyzing an amorphous-like alloy plate layer 20 using anX-ray diffractometer;

FIG. 2C is a diagram illustrating another example of the diffractionprofile obtained by analyzing an amorphous-like alloy plate layer 20using an X-ray diffractometer;

FIG. 3A is a graph (part 1 thereof) illustrating the results ofevaluating the corrosion resistance of an alloy plate coated material100 obtained in an Example;

FIG. 3B is a graph (part 2 thereof) illustrating the results ofevaluating the corrosion resistance of an alloy plate coated material100 obtained in an Example;

FIG. 3C is a graph (part 3 thereof) illustrating the results ofevaluating the corrosion resistance of an alloy plate coated material100 obtained in an Example;

FIG. 4 is a diagram for explaining the method for measuring the contactresistance of an alloy plate coated material 100 obtained in an Example;and

FIG. 5 is a graph illustrating the results of measuring the contactresistance of an alloy plate coated material 100 obtained in an Example.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, the alloy plate coated material 100 of the presentembodiment will be explained.

As illustrated in FIG. 1, the alloy plate coated material 100 of thepresent embodiment includes, on a base material 10, an alloy plate layer20 which is formed from a M1-M2-M3 alloy (provided that M1 is at leastone element selected from Ni, Fe, Co, Cu, Zn and Sn; M2 is at least oneelement selected from Pd, Re, Pt, Rh, Ag and Ru; and M3 is at least oneelement selected from P and B) and constitutes the outermost layer. Inthe present embodiment, the alloy plate layer 20 is a plated layer inwhich the molar ratio of M1 to M2 (M1/M2) is 0.005 to 0.5.

The base material 10 is not particularly limited. Examples of the basematerial 10 include steel, stainless steel, Al, Al alloy, Ti, Ti alloy,Cu, Cu alloy, Ni, and Ni alloy. In particular, it is preferred to usestainless steel.

The stainless steel sheet is not particularly limited. Examples of thestainless steel sheet include those made of stainless steel material,such as SUS316, SUS316L and SUS304. Various types of stainless steelsheets may be mentioned, such as martensite-based, ferrite-based andaustenite-based ones, among which austenite-based stainless steel sheetsmay be preferred.

Furthermore, it is preferable that a predetermined passivation film isformed on the surface of the stainless steel sheet. Regarding thepredetermined passivation film, a passivation film in which the Cr/Ovalue (molar ratio of Cr/O) and the Cr/Fe value (molar ratio of Cr/Fe)measured at the surface of the passivation film by an Auger electronspectroscopy analysis are in the following ranges. That is, the Cr/Ovalue is preferably in the range of 0.09 to 0.20. Furthermore, the Cr/Fevalue is preferably in the range of 0.55 to 0.80.

According to the present embodiment, when the Cr/O value and the Cr/Fevalue at the surface of the passivation film formed on the stainlesssteel sheet used as the base material 10, as measured by an Augerelectron spectroscopy analysis, is controlled to the ranges describedabove, the alloy plate coated material 100 thus obtainable has excellentcorrosion resistance and electrical conductivity.

In the present embodiment, the Cr/O value and Cr/Fe value can bemeasured by Auger electron spectroscopy analysis using the method below.First, a scanning-type Auger electron spectroscopy analyzer (AES) isused to measure the surface of the passivation film of the stainlesssteel, and the atomic percentages of Cr, O, and Fe at the surface of thepassivation film are calculated. Five locations at the surface of thepassivation film are measured using a scanning-type Auger electronspectroscopy analyzer, and the obtained results may be averaged therebyto calculate the Cr/O value (at % of Cr/at % of O) and the Cr/Fe value(at % of Cr/at % of Fe). For example, among the obtained peaks by themeasurement using a field emission Auger microprobe, a peak given at 510to 535 eV represents the peak of Cr, a peak given at 485 to 520 eVrepresents the peak of O, and a peak given at 570 to 600 eV representsthe peak of Fe. The atomic percentages of Cr, O, and Fe are to bemeasured when the sum of Cr, O, and Fe is 100 at %.

In the present embodiment, the method of forming the passivation film atthe surface of the stainless steel sheet 10 is not particularly limited.Examples of the method include a method of immersing a stainless steelmaterial, such as SUS316L as described above, which constitutes thestainless steel sheet 10, into a sulfuric acid aqueous solution.

When a stainless steel material is immersed in a sulfuric acid aqueoussolution to form the passivation film, the sulfuric acid concentrationin the sulfuric acid aqueous solution may preferably be 20 to 25 vol %.The temperature when immersing the stainless steel material maypreferably be 50° C. to 70° C., and more preferably 60° C. to 70° C. Thetime for the stainless steel material to be immersed in the sulfuricacid aqueous solution may preferably be 5 to 600 seconds, and morepreferably 5 to 300 seconds.

The shape and form of the stainless steel sheet 10 are not particularlylimited, and may be appropriately selected depending on the use. Forexample, the stainless steel sheet 10 may be used after being workedinto a necessary shape or form depending on its use, such as aconductive metal component worked into a linear form or a plate orsheet-like form, a conductive member obtained by working a plate orsheet into an irregular form, and an electronic device component workedinto a spring-like or tubular form. The thickness (such as diameter andsheet or plate thickness) of the stainless steel sheet 10 is also notparticularly limited, and may be appropriately selected depending on theuse.

In the present embodiment, the alloy plate coated material 100 can beused as a separator for fuel cells. Such a separator for fuel cells isused as a member of a fuel cell that constitutes a fuel cell stack, andhas a function to supply an electrode with fuel gas or air through gasflow channels and a function to collect electrons generated at theelectrode. When the alloy plate coated material 100 is used as aseparator for fuel cells, the surface of the base material 10 to be usedmay be preliminarily formed with irregularities (gas flow channels) thatfunction as flow channels for fuel gas or air. The method of formingsuch gas flow channels is not particularly limited, but a method offorming the gas flow channels by press working may be mentioned, forexample.

Alloy Plate Layer 20

The alloy plate layer 20 is a plated layer formed as the outermost layerin order to enhance the corrosion resistance and abrasion resistance ofthe alloy plate coated material 100 and to impart electricalconductivity. The alloy plate layer 20 is formed from a M1-M2-M3 alloy(provided that M1 is at least one element selected from Ni, Fe, Co, Cu,Zn and Sn; M2 is at least one element selected from Pd, Re, Pt, Rh, Agand Ru; and M3 is at least one element selected from P and B), and themolar ratio of M1 to M2 (M1/M2) is 0.005 to 0.5.

Meanwhile, the method for forming the alloy plate layer 20 is notparticularly limited, and can be formed by electrolytic plating,electroless plating, sputtering or the like. However, as will bedescribed below, it is preferable that the alloy plate layer 20 isformed by electroless plating.

M1 in the M1-M2-M3 alloy is at least one element selected from Ni, Fe,Co, Cu, Zn and Sn. One element may be solely used, or two or moreelements may be used in combination, such as in Ni—Fe, Ni—Co and Ni—Cu.Each element that constitutes M1 is an element having a property capableof independently forming a plated layer on the base material 10. In viewof preventing the plating liquid from self-decomposition and enhancingthe stability of the plating liquid, it is preferred to use at least oneelement selected from Ni and Co as M1, and particularly preferred is touse Ni.

M2 in the M1-M2-M3 alloy is at least one element selected from Pd, Re,Pt, Rh, Ag and Ru. One element may be solely used, or two or moreelements may be used in combination. Each element that constitutes M2 isan element acting as a catalyst for the reaction of a reductant in theplating bath when deposited on the base material 10, i.e., has an actionto continuously progress the metal deposition reaction. In view ofkeeping low cost, it is preferred to use at least one element selectedfrom Pd and Ag as M2, and particularly preferred is to use Pd.

M3 in the M1-M2-M3 alloy is at least either one element selected from Pand B. One element may be solely used, or these elements may be used incombination, as P—B. Each element that constitutes M3 is a metalloidthat constitutes a reductant in the plating bath for forming the alloyplate layer 20, and will be unavoidably included into the alloy platelayer 20 in general when the alloy plate layer 20 is formed. In view ofpreventing the plating liquid from self-decomposition and enhancing thestability of the plating liquid, it is preferred to use P as M3.

The ratio of each element in the M1-M2-M3 alloy may preferably be suchthat M1 is 15 to 65 at %, M2 is 20 to 60 at %, and M3 is 15 to 40 at %,and more preferably such that M1 is 20 to 50 at %, M2 is 30 to 50 at %,and M3 is 20 to 30 at %. Furthermore, in regard to the alloy platecoated material 100, a small amount of unavoidable impurities may beincluded in the M1-M2-M3 alloy, to the extent that corrosion resistanceand abrasion resistance are not significantly deteriorated. Examples ofsuch unavoidable impurities include a heavy metal, such as Pb, Tl andBi, which is added as a stabilizer that prevents the plating liquid fromself-decomposition and stabilizes the plating liquid. In view ofreducing the environmental load, Bi may preferably be used as thestabilizer. When the composition ratio of the M1-M2-M3 alloy is adjustedto the range described above, the alloy plate layer 20 can besatisfactorily formed on the base material 10, and thus the alloy platecoated material 100 can have excellent corrosion resistance and abrasionresistance.

Respective elements of the M1-M2-M3 alloy may be arbitrarily combined tobe used. In view of preventing the plating liquid fromself-decomposition and enhancing the stability of the plating liquid,Ni—Pd—P alloy, Ni—Pt—P alloy, Co—Pd—P alloy and Co—Ag—P alloy arepreferred, and Ni—Pd—P alloy is particularly preferred.

While the method of forming the alloy plate layer 20 of the M1-M2-M3alloy is not particularly limited as described above, when a method offormation by electroless plating is employed, there may be used aplating bath which contains elements represented by M1, M2 and M3 and towhich a reductant and a complexing agent are added (underlying alloyelectroless plating bath).

For example, when forming the alloy plate layer 20 of Ni—Pd—P alloy, theelectroless alloy plating bath to be used can be obtained by mixing anickel plating bath and a palladium plating bath which are ordinarilyused. Examples of the nickel plating bath include a plating bath thatcontains: a nickel salt such as nickel chloride, nickel sulfate, nickelnitrate and nickel acetate; a phosphorus-containing reductant such ashypophosphite; and a complexing agent such as citric acid. Examples ofthe palladium plating bath include a plating bath that contains: apalladium salt such as palladium chloride; a phosphorus-containingreductant such as hypophosphite and phosphite; a reducing agent such asformic acid; and a complexing agent such as thiodiglycolic acid.

Meanwhile, on the occasion of producing an alloy electroless platingbath by mixing a nickel plating bath and a palladium plating bath, it ispreferable to use nickel chloride, nickel sulfate or the like as thenickel salt, and to use palladium chloride or the like as the palladiumsalt. In regard to the mixing ratio between the nickel plating bath andthe palladium plating bath, the molar ratio of Ni atoms and Pd atoms inthe alloy electroless plating bath is such that the proportion Ni:Pd(molar ratio) is 0.62:1.0 to 3.32:1.0, preferably 0.88:1.0 to 2.68:1.0,and more preferably 0.88:1.0 to 2.14:1.0. Thereby, according to thepresent embodiment, the alloy plate layer 20 formed from a Ni—Pd—P alloythus obtainable is produced into an amorphous-like configuration, andcorrosion resistance and electrical conductivity can all be enhanced.

Meanwhile, in the present embodiment, the amorphous-like structure forthe alloy plate layer 20 represents a structure that is substantiallyconstituted of an amorphous (non-crystalline) form of a M1-M2-M3 alloy,and refers to a structure which may contain a slight amount of crystalsof the M1-M2-M3 alloy. Such crystals may have a crystal structure thatis unavoidably formed in the alloy plate layer 20 by the influence ofthe impurities included into the alloy plate layer 20 during the coursein which the alloy plate layer 20 is formed on the base material 10, orthe like.

Specifically, regarding the amorphous-like structure according to thepresent embodiment, there may be mentioned an example in which thediffraction profile obtained when the alloy plate layer 20 is analyzedby a grazing incidence X-ray diffraction method using an X-raydiffractometer, has a shape which has no sharp peaks originating fromcrystals containing at least one element selected from among M1, M2 andM3. That is, in a case in which the alloy plate layer 20 is formed froma Ni—Pd—P alloy, and a crystal containing at least one of Ni, Pd and Pexists in the alloy plate layer 20, sharp peaks originating fromcrystals are detected from the diffraction profile thus obtainable.Meanwhile, in the graph of FIG. 2A obtained by analyzing the Pd crystalstructure, peaks originating from Pd crystals are detected atdiffraction angles (2θ) near, for example, “40°”, “46°”, and “68°”. Inthe present embodiment, in a case in which such sharp peaks originatingfrom crystals are not detected in the alloy plate layer 20, it can bedetermined that the alloy plate layer 20 has an amorphous-likestructure.

Alternatively, regarding the amorphous-like structure, there may bementioned an example in which the diffraction profile obtained when thealloy plate layer 20 is analyzed by a grazing incidence X-raydiffraction method using an X-ray diffractometer, has a shape which hasa halo originating from an amorphous structure. That is, in a case inwhich the alloy plate layer 20 substantially has an amorphous structure,as illustrated in FIGS. 2B and 2C, a halo originating from an amorphousstructure (a smooth curve at diffraction angles (2θ) near 20° to 60° isdetected from the diffraction profile. Meanwhile, FIG. 2B illustratesthe diffraction profile obtained in Example 3 that is described below,and FIG. 2C illustrates the diffraction profile obtained in Example 4that is described below. These illustrate examples of the diffractionprofiles obtainable in a case in which the alloy plate layer 20 isformed from a Ni—Pd—P alloy having an amorphous structure. In thepresent embodiment, in a case in which such a halo originating from anamorphous structure is exhibited in the alloy plate layer 20, it can bedetermined that the alloy plate layer 20 has an amorphous-likestructure.

In the above description, the case in which the alloy plate layer 20 isformed from a Ni—Pd—P alloy has been illustrated as an example. However,even in a case in which the alloy plate layer 20 is formed from an alloyother than the Ni—Pd—P alloy, similarly, an alloy electroless platingbath obtained by appropriately preparing a plating bath which containsthe respective elements of M1, M2 and M3 and has a reducing agent and acomplexing agent added thereto, may be used. In this case, it isdesirable that the molar ratio between the M1 atom and the M2 atom,M1:M2 (molar ratio), in the alloy electroless plating bath containingthe various elements of M1, M2 and M3 has the same value as theproportion Ni:Pd (molar ratio) mentioned above.

Meanwhile, it is preferable that the alloy plate layer 20 is formedusing the alloy electroless plating bath described above, under theconditions of a pH of 4.0 to 7.0, a bath temperature of 30° C. to 50°C., and an immersion time of 5 to 20 minutes.

Furthermore, the thickness of the alloy plate layer 20 thus formed ispreferably 5 to 100 nm, and more preferably 30 to 50 nm. When thethickness of the alloy plate layer 20 is adjusted to the range describedabove, the alloy plate coated material 100 thus obtainable can haveexcellent corrosion resistance and abrasion resistance.

For example, when the alloy plate coated material 100 according to thepresent embodiment is used as a separator for fuel cells, the basematerial 10 on which such an alloy plate layer 20 alloy plate layer 20is to be formed may be preliminarily formed with gas flow channels suchas by press working, as described above. According to the presentembodiment, the alloy plate layer 20 can be formed on such a basematerial 10, which is preliminarily formed with gas flow channels,thereby to effectively prevent cracks in the alloy plate layer 20 of theseparator for fuel cells to be obtained. This will be described in moredetail. When the alloy plate layer 20 is formed on a base material 10 onwhich gas flow channels are not formed and thereafter the gas flowchannels are formed such as by press working, a problem may arise inthat cracks occur in the alloy plate layer 20 due to stresses appliedwhen the gas flow channels are formed. However, such a problem can besolved by preliminarily forming the gas flow channels on the basematerial 10 and thereafter forming the alloy plate layer 20 as describedabove. In particular, according to the present embodiment, when thealloy plate layer 20 is formed by electroless plating, the alloy platelayer 20 can be uniformly formed for the gas flow channel part havingirregularities while suppressing the occurrence of unformed parts of thealloy plate layer 20.

In the present embodiment, the alloy plate layer 20 may be formeddirectly on the base material 10, but a modifying layer may be providedbetween the base material 10 and the alloy plate layer 20 in order toenhance the interfacial adhesion property of the alloy plate layer 20.The modifying layer may appropriately be formed in accordance withproperties of the base material 10 and the alloy plate layer 20. In viewof enhancing the interfacial adhesion property with the alloy platelayer 10, the modifying layer may preferably be a layer that containsthe same element or elements as M1 of the M1-M2-M3 alloy whichconstitutes the alloy plate layer 20. For example, when Ni—Pd—P alloy isemployed as the alloy plate layer 20, the modifying layer may preferablybe a Ni-based layer that contains Ni as the element represented by M1.When such a Ni-based layer is formed by electroless reduction plating,the Ni-based layer may be a Ni—P plated layer. One modifying layer maybe provided, or two or more modifying layers may also be provided. Whentwo or more modifying layers are provided, components that constituterespective layers may be or may not be the same. The method of formingthe modifying layer or layers is not particularly limited. The modifyinglayer or layers can be formed by an appropriate method such aselectrolytic plating, electroless plating, and sputtering.

Furthermore, the alloy plate layer 20 of the present embodiment is aplated layer in which the molar ratio of M1 to M2 (M1/M2) is 0.005 to0.5, as described above.

In the present embodiment, it is preferable that the alloy plate layer20 is formed from an alloy having an amorphous-like structure, asdescribed above.

Furthermore, the molar ratio of M1 to M2 (M1/M2) in the M1-M2-M3 alloythat constitutes the alloy plate layer 20 is 0.005 to 0.5, preferably0.008 to 0.44, and more preferably 0.008 to 0.33. When the molar ratio(M1/M2) for the alloy plate layer 20 is adjusted to the range describedabove, the alloy plate coated material 100 thus obtainable has excellentcorrosion resistance and electrical conductivity.

According to the present embodiment, when the alloy plate layer 20 isconfigured such that the molar ratio of M1 to M2 (M1/M2) is in the rangedescribed above, since the alloy plate coated material 100 thusobtainable is non-crystalline, the alloy plate coated material 100 hascharacteristics such as high strength, high toughness, high corrosionresistance, excellent magnetic characteristics (high magneticpermeability and low coercive force), and excellent moldingprocessability. Furthermore, it is considered that when the molar ratio(M1/M2) is adjusted to an appropriate value, corrosion resistance isenhanced, and electrical conductivity is also enhanced. Thereby, thealloy plate coated material 100 thus obtainable can have excellentelectrical conductivity in addition to corrosion resistance.

According to the present embodiment, in regard to the alloy plate layer20 thus formed, the method for configuring the molar ratio of M1 to M2(M1/M2) to the range described above is not particularly limited;however, a method of controlling the plating conditions when the alloyplate layer 20 is formed by electroless plating. In this case, regardingthe plating conditions for electroless plating, for example, the alloyelectroless plating bath described above is used, and the conditions ofa pH of 4.0 to 7.0, a bath temperature of 30° C. to 50° C., and animmersion time of 5 to 20 minutes can be used.

Furthermore, it is preferable that the alloy plate layer 20 has a glasstransition point. In the present embodiment, when the alloy plate layer20 has a glass transition point, the corrosion resistance and electricalconductivity of the alloy plate coated material 100 thus obtainable canbe further enhanced.

Here, examples of the method of checking whether the alloy plate layer20 has a glass transition point include known methods such as a methodof detecting the temperature when the coefficient of thermal expansionchanges rapidly while the temperature of the alloy plate layer 20 isslowly increased or decreased, using a thermomechanical analysisapparatus (TMA); and a method of measuring heat absorption or heatgeneration while the temperature of the alloy plate layer 20 is slowlyincreased or decreased, and detecting the temperature at which a shiftin the baseline in the DSC curve thus obtainable is observed.

The glass transition point of the alloy plate layer 20 is notparticularly limited; however, the glass transition point is preferably250° C. to 400° C., and more preferably 300° C. to 350° C.

According to the alloy plate coated material 100 related to the presentembodiment, the alloy plate layer 20 formed as the outermost layer isformed from a M1-M2-M3 alloy, with the molar ratio of M1 to M2 (M1/M2)being 0.005 to 0.5, and both corrosion resistance and electricalconductivity can be enhanced. Therefore, the alloy plate coated material100 of the present embodiment is suitably used as an electrical contactmaterial used in connectors, switches, printed wiring boards, and thelike.

Meanwhile, regarding the method of producing an alloy plate coatedmaterial having an alloy plate layer formed on the surface, a method offorming, on a base material, an amorphous alloy plate layer formed froman amorphous alloy such as a nickel-based alloy has been conventionallyused. However, when simply an amorphous alloy plate layer formed from anamorphous alloy is formed, corrosion resistance is enhanced; however,electrical conductivity becomes insufficient. Thus, there is a problemthat satisfactory characteristics of an electrical contact material arenot obtained.

Particularly, in a case in which the alloy plate coated material is usedas a separator for a fuel cell, high electrical conductivity is requiredin addition to high corrosion resistance. That is, since a separator fora fuel cell is exposed to an environment at a high temperature in anacidic atmosphere in the fuel cell, high corrosion resistance isrequired. In addition, in order to collect the electrons generated inthe electrode, high electrical conductivity is required.

In this regard, according to the alloy plate coated material 100 relatedto the present embodiment, when the alloy plate layer 20 of a M1-M2-M3alloy formed as the outermost layer is produced into a plated layerhaving a molar ratio of M1 to M2 (M1/M2) of 0.005 to 0.5, that is, evenif the alloy plate coated material 100 is configured to benon-crystalline (amorphous), when the alloy plate layer 20 is producedinto a plated layer having the molar ratio of elements that constitutethe M1-M2-M3 alloy controlled to a predetermined value, both corrosionresistance and electrical conductivity can be enhanced. Thus, the alloyplate coated material 100 can be suitably used as a separator for a fuelcell.

Furthermore, according to the alloy plate coated material 100 related tothe present embodiment, when the alloy plate layer 20 of the M1-M2-M3alloy formed as the outermost layer is produced into an alloy platelayer having the amorphous-like structure described above, bothcorrosion resistance and electrical conductivity can be enhanced. Thus,the alloy plate coated material 100 can be suitably used as a separatorfor a fuel cell.

EXAMPLES

Hereinafter, the present invention will be more specifically describedwith reference to examples, but the present invention is not limited tothese examples.

Example 1

First, a stainless steel material (SUS316L) was prepared as a basematerial 10. Next, the base material 10 thus prepared was subjected toan electroless plating treatment under the conditions of 38° C. for 4minutes using a plating bath obtained by mixing a palladium plating bathand a nickel plating bath such as described below at a proportion ofpalladium plating bath:nickel plating bath=5.7:1 (volume ratio). Thus, aNi—Pd—P alloy layer having a thickness of 40 nm was formed as an alloyplate layer 20 on the base material 10, and thereby an alloy platecoated material 100 was obtained. Meanwhile, regarding the palladiumsalt, reducing agent and complexing agent used in the plating baths,conventionally known compounds were used. Also, the proportion Ni:Pd(molar ratio) in the plating bath obtained by mixing a palladium platingbath and a nickel plating bath was 1.14:1.0.

Palladium Plating Bath

Palladium salt: an amount to make the amount of Pd in the palladiumplating bath 0.15 wt %

Reducing agent: 1.8 wt %

Complexing agent: 0.63 wt %

Water: 97.2 wt %

pH: 5.5

Nickel Plating Bath

Nickel salt (nickel chloride): 1.8 wt %

Reducing agent (sodium hypophosphite): 2.4 wt %

Complexing agent: 2.4 wt %

Water: 93.2 wt %

pH: 5.2

Example 2

An alloy plate coated material 100 was obtained in the same manner as inExample 1, except that the conditions for the electroless platingtreatment employed at the time of forming the alloy plate layer 20 werechanged to 38° C., a duration of 8 minutes, and pH: 6.0, and a Ni—Pd—Palloy layer having a thickness of 80 nm was formed as the alloy platelayer 20 on the base material 10.

Comparative Example 1

An alloy plate coated material 100 was obtained in the same manner as inExample 1, except that as the plating bath used for the electrolessplating treatment at the time of forming the alloy plate layer 20, aplating bath obtained by mixing a palladium plating bath and a nickelplating bath at a proportion of palladium plating bath:nickel platingbath=1:2 (volume ratio) was used. Meanwhile, the Ni:Pd (molar ratio) inthe plating bath obtained by mixing a palladium plating bath and anickel plating bath was 0.1:1.0.

Example 3

First, a stainless steel material (SUS316L) was prepared as a basematerial 10. Then, the base material 10 thus prepared was subjected toelectrolytic degreasing in an aqueous alkali solution having acommercially available degreasing agent (manufactured by Nippon QuakerChemical, Ltd., Formula 618-TK2) dissolved therein. Subsequently, thedegreased base material 10 was washed with water, and then was washedwith an acid by immersing the base material for 15 seconds in an aqueoussolution of sulfuric acid (concentration 25 wt %) at 70° C.Subsequently, the base material was subjected to an electroless platingtreatment under the conditions of 37° C. and pH 5.95 for 2 minutes,using a plating bath obtained by mixing a palladium plating bath and anickel plating bath such as described below at a proportion of palladiumplating bath:nickel plating bath=5.67:1.0 (volume ratio). Thus, aNi—Pd—P alloy layer having a thickness of 40 nm was formed as an alloyplating layer 20 on the base material 10, and an alloy plate coatedmaterial 100 was obtained. Furthermore, the proportion Ni:Pd (molarratio) in the plating bath obtained by mixing a palladium plating bathand a nickel plating bath was 0.88:1.0. Regarding the reducing agent andthe complexing agent in the plating bath, conventionally known compoundswere used. Furthermore, the molar ratio of M1 (Ni) to M2 (Pd) (Ni/Pd) inthe alloy plate layer 20 thus formed was 0.008.

Palladium Plating Bath

Palladium salt (palladium chloride): 0.28 wt %

Reducing agent: 1.80 wt %

Complexing agent: 0.63 wt %

Water: 97.3 wt %

pH: 6.0

Nickel Plating Bath

Nickel salt (nickel sulfate): 2.0 wt %

Reducing agent: 2.6 wt %

Complexing agent: 2.6 wt %

Water: 92.8 wt %

pH: 4.3

Example 4

An alloy plate coated material 100 was obtained in the same manner as inExample 3, except that an electroless plating treatment was appliedunder the conditions of 37° C. and pH 6.34 for 12 minutes using aplating bath obtained by mixing the palladium plating bath and thenickel plating bath described in Example 3 at a proportion of palladiumplating bath:nickel plating bath=3:1 (volume ratio), and thus a Ni—Pd—Palloy layer having a thickness of 40 nm was formed as the alloy platelayer 20 on the base material 10. Furthermore, the proportion Ni:Pd(molar ratio) in the plating bath obtained by mixing a palladium platingbath and a nickel plating bath was 1.88:1.0.

Example 5

An alloy plate coated material 100 was obtained in the same manner as inExample 3, except that an electroless plating treatment was appliedunder the conditions of 55° C. and pH 6.7 for 5 minutes using a platingbath obtained by mixing the palladium plating bath and the nickelplating bath described in Example 3 at a proportion of palladium platingbath:nickel plating bath=1.86:1.0 (volume ratio), and thereby a Ni—Pd—Palloy layer having a thickness of 40 nm was formed as an alloy platelayer 20 on the base material 10. Furthermore, the proportion Ni:Pd(molar ratio) in the plating bath obtained by mixing a palladium platingbath and a nickel plating bath was 2.68:1.0. Meanwhile, regarding thereducing agent and the complexing agent in the plating bath,conventionally known compounds were used. Furthermore, the molar ratioof M1 (Ni) to M2 (Pd) (Ni/Pd) in the alloy plate layer 20 thus formedwas 0.44.

Measurement of Amounts of Metals in Alloy Plate Layer 20

The amounts of metals in the film were measured using the alloy platecoated materials 100 obtained in Examples 3 and 5. Specifically, each ofthe alloy plate coated materials 100 was cut into a size of the alloyplate film 20 of 40 mm in length and 40 mm in width, and the alloy platefilm 20 was dissolved by immersing the film in a 60% aqueous solution ofnitric acid (volume 10 ml) at 60° C. The alloy plate coated material 100was removed, and water was added to the aqueous solution in which thealloy plate film 20 was dissolved, to make up 100 ml. Subsequently, themass concentrations (g/L) of the ions (Ni, Pd and P) eluted into theaqueous solution were measured using an inductively coupled plasmaemission analyzer (manufactured by Shimadzu Corporation, ICPE-9000), andthe molar ratio in the film was calculated from the measurement results,the amounts of metals obtained from the measurement results of ICP thusobtained, and the surface area of the dissolved plated layer. Theresults are presented in Table 1.

TABLE 1 Molar Contact ratio in alloy plate layer 20 resistance (Ni/Pd)[mW × cm²] Example 3 0.008 0.5 Example 4 Not measured 0.43 Example 50.44 0.69 Comparative Example 2 Alloy plate layer 20 is absent 10.9Comparative Example 3 Not measured 0.74

Comparative Example 2

The stainless steel material (SUS316L) used in Example 3 described abovewas prepared, and the following evaluation was carried out withoutforming an alloy plate layer 20 on this stainless steel material.

Comparative Example 3

An alloy plate coated material 100 was obtained in the same manner as inExample 3, except that an electroless plating treatment was appliedunder the conditions of 55° C. and pH 7.3 for 5 minutes using a platingbath obtained by mixing the palladium plating bath and the nickelplating bath described in Example 3 at a proportion of palladium platingbath:nickel plating bath=1:1 (volume ratio), and thus a Ni—Pd—P alloylayer having a thickness of 40 nm was formed as an alloy plate layer 20on the base material 10. Meanwhile, regarding the palladium salt, thereducing agent and the complexing agent in the plating bath,conventionally known compounds were used. Furthermore, the proportionNi:Pd (molar ratio) in the plating bath obtained by mixing a palladiumplating bath and a nickel plating bath was 4.99:1.0.

Analysis of Alloy Plate Layer 20 Using X-Ray Diffractometer

For the alloy plate coated materials 100 obtained in Examples 3 and 4and Comparative Examples 2 and 3, an X-ray diffraction analysis wascarried out by a grazing incidence X-ray diffraction method using anX-ray diffractometer (manufactured by Rigaku Corporation, product No.:RINT-2500). Meanwhile, the analysis results of Example 3 are illustratedin FIG. 2B, and the analysis results of Example 4 are illustrated inFIG. 2C. According to the results, in Example 3, peaks originating fromcrystals were not observed at the positions at which peaks of M1 to M3metals appear, and in Comparative Example 2, peaks that were consideredto be originating from the crystals in the base material were observed.

Evaluation of Corrosion Resistance (Part 1 Thereof)

Next, for the alloy plate coated materials 100 obtained in Example 1 andComparative Example 1, an evaluation of the corrosion resistance wascarried out. Specifically, each of the alloy plate coated materials 100was masked along the edge faces with a polyimide tape so that an areawhich measured 35 mm in length and 20 mm in width was exposed, and thealloy plate coated material was immersed in an aqueous solution ofsulfuric acid (volume 80 ml, pH: 1.0) at 90° C. for 100 hours.Subsequently, the alloy plate coated material 100 was removed, and themass concentrations (g/L) of the ions (Ni, Pd, P, Fe, Cr and Mo) elutedfrom the alloy plate coated material 100 into the aqueous solution ofsulfuric acid were measured using an inductively coupled plasma emissionanalyzer (manufactured by Shimadzu Corporation, ICPE-9000). Furthermore,as a comparison, an evaluation of corrosion resistance was carried outalso for Comparative Example 2 which was a stainless steel material(SUS316L) conventionally used as a material for a separator for a fuelcell, by similarly immersing the stainless steel material in an aqueoussolution of sulfuric acid, and measuring the mass concentrations (g/L)of the ions (Ni, Pd, P, Fe, Cr and Mo) eluted into the aqueous solutionof sulfuric acid. The results are presented in FIG. 3A. Meanwhile, thegraph of FIG. 3A shows the values of the ion elution concentration(ppm).

According to the results of FIG. 3A, 10 ppm of metals was eluted inExample 1. On the other hand, in SUS316L (Comparative Example 2) that isused as a material for a conventional separator for a fuel cell or thelike, 39 ppm of metals was eluted. In Example 1, elution of ions fromthe base material could be effectively suppressed as compared toComparative Example 2, and it was confirmed that the material exhibitedexcellent corrosion resistance. Furthermore, although it is not shown inFIG. 3A, elution of ions from the base material could also beeffectively suppressed in Example 2 to the same extent as the extent ofExample 1, and it was confirmed that the material exhibited excellentcorrosion resistance. On the other hand, according to the results ofFIG. 3A, in Comparative Example 1, 18 ppm of metals was eluted, and theamount of elution of ions from the base material was larger compared toExample 1, and it was confirmed that the material exhibited poorcorrosion resistance.

Evaluation of Corrosion Resistance (Part 2 Thereof)

Subsequently, for the alloy plate coated materials 100 obtained inExamples 3 and 4 and Comparative Example 3, an evaluation of corrosionresistance was carried out. For Example 3, specifically, the alloy platecoated material 100 was masked along the edge faces with a polyimidetape so that an area which measured 40 mm in length and 37 mm in widthwas exposed, and the alloy plate coated material was immersed in anaqueous solution of sulfuric acid (volume 90 ml, pH: 3.0) at 90° C. for100 hours. Subsequently, the alloy plate coated material 100 wasremoved, and the mass concentrations (g/L) of the ions (Ni, Pd, P, Fe,Cr and Mo) eluted from the alloy plate coated material 100 into theaqueous solution of sulfuric acid were measured using an inductivelycoupled plasma emission analyzer (manufactured by Shimadzu Corporation,ICPE-9000). Furthermore, as a comparison, an evaluation of corrosionresistance was also carried out for Comparative Example 2 which was astainless steel material (SUS316L) conventionally used as a material fora separator for a fuel cell, by similarly immersing the stainless steelmaterial in an aqueous solution of sulfuric acid and measuring the massconcentrations (g/L) of the ions (Ni, Pd, P, Fe, Cr and Mo) eluted intothe aqueous solution of sulfuric acid. The results are presented in FIG.3B. In addition, the graph of FIG. 3B shows the values of the ionelution concentration (ppm). In regard to the evaluation of corrosionresistance (part 2 thereof) and the evaluation of corrosion resistance(part 3 thereof) that will be described below, since the pH of thesulfuric acid used in the test was higher (changed from 1.0 to 3.0)compared to the evaluation of corrosion resistance (part 1 thereof)described above, the values of the ion elution concentration (ppm) wererelatively lower values.

According to the results of FIG. 3B, 0.062 ppm of metals was eluted inComparative Example 2, and 2.219 ppm of metals was eluted in ComparativeExample 3. 0.042 ppm of metals was eluted in Example 3, and 0.023 ppm ofmetals was eluted in Example 4.

It was confirmed from the results of Table 1 and FIG. 3B that in Example3 in which an alloy plate layer 20 having a molar ratio of M1 (Ni) to M2(Pd) (Ni/Pd) of 0.005 to 0.5 was formed on a base material 10, elutionof ions from the base material could be effectively suppressed ascompared to SUS316L (Comparative Example 2) that is used as a materialfor a conventional separator for a fuel cell or the like, and Example 3exhibited excellent corrosion resistance. On the other hand, it wasconfirmed from the results of FIG. 3B that in Comparative Example 3, theamount of elution of ions from the base material was larger compared tothe amounts of Example 3 and Example 4, and Comparative Example 3exhibited poor corrosion resistance.

Evaluation of Corrosion Resistance (Part 3 Thereof)

Subsequently, an evaluation of corrosion resistance was carried out forthe alloy plate coated materials 100 obtained in Example 5 andComparative Example 2. Specifically, each of the alloy plate coatedmaterials 100 was masked along the edge faces with a polyimide tape sothat an area which measured 40 mm in length and 37 mm in width wasexposed, and the alloy plate coated material was immersed in an aqueoussolution of sulfuric acid (volume 90 ml, pH: 3.0) at 90° C. for 100hours. Subsequently, the alloy plate coated material 100 was removed,and the mass concentrations (g/L) of the ions (Ni, Pd, P, Fe, Cr and Mo)eluted from the alloy plate coated material 100 into the aqueoussolution of sulfuric acid were measured using an inductively coupledplasma emission analyzer (manufactured by Shimadzu Corporation,ICPE-9000). Furthermore, as a comparison, an evaluation of corrosionresistance was also carried out for Comparative Example 2 which was astainless steel material (SUS316L) conventionally used as a material fora separator for a fuel cell, by similarly immersing the stainless steelmaterial in an aqueous solution of sulfuric acid and measuring the massconcentrations (g/L) of the ions (Ni, Pd, P, Fe, Cr and Mo) eluted intothe aqueous solution of sulfuric acid. The results are presented in FIG.3C. In addition, the graph of FIG. 3C shows the values of the ionelution concentration (ppm).

According to the results of FIG. 3C, 0.88 ppm of metals was eluted inComparative Example 2, and 0.85 ppm of metals was eluted in Example 5.

From the results of Table 1 and FIG. 3C, it was confirmed that inExample 5 in which an alloy plate layer 20 having a molar ratio of M1(Ni) to M2 (Pd) (Ni/Pd) of 0.005 to 0.5 was formed on the base material10, elution of ions from the base material could be effectivelysuppressed as compared to SUS316L (Comparative Example 2) that is usedas a material for a conventional separator for a fuel cell or the like,and excellent corrosion resistance was obtained.

Measurement of Contact Resistance Value (Part 1)

Each of the alloy plate coated materials 100 obtained in Example 1 wasused to form a measurement system as shown in FIG. 4, and measurement ofthe contact resistance value was performed using the measurement systemformed. The measurement system shown in FIG. 4 is configured of: thealloy plate coated material 100; carbon cloths 200, which are used asbase materials of gas diffusion layers in a separator for fuel cells;gold plate coated copper electrodes 300; a digital multimeters 400; andan ammeter 500. Specifically, at the time of measurement of the contactresistance value, the alloy plate coated material 100 was first workedinto a size of width of 20 mm, length of 20 mm and thickness of 1.27 mmand fixed by being interposed between the gold plate coated copperelectrodes 300 via the carbon cloths 200 (part number: TGP-H-090,available from Toray Industries, Inc), and the measurement system wasthus formed as shown in FIG. 4. Then, the contact resistance valuesbetween the upper and lower carbon cloths 200 sandwiching the test piecewere measured using an ohm meter (Milli-Ohm HiTESTER 3540 available fromHIOKI E.E. CORPORATION) within a range of load of 5 to 20 (kg/cm2) whileapplying a constant load to the copper electrodes 300. Measurementresults are shown in FIG. 5.

FIG. 5 also shows values of the measured contact resistance values ofSUS316L (Comparative Example 2) as comparative data. The contactresistance values of SUS316L (Comparative Example 2) were obtained byperforming measurement in the above-described measurement system asshown in FIG. 4 after working SUS316L into a size of width of 20 mm,length of 20 mm and thickness of 1.0 mm.

According to the results of FIG. 5, in Example 1, the contact resistancehad a lower value compared to SUS316L (Comparative Example 2) that isused as a material for a separator for a fuel cell or the like, andconsequently, excellent electrical conductivity was obtained.

Measurement of Contact Resistance Value (Part 2)

Next, alloy plate coated materials 100 were processed into a size of 20mm in width, 20 mm in length, and 1.27 mm in thickness using the alloyplate coated materials 100 obtained in Examples 3 to 5 and ComparativeExamples 2 and 3, and using a measurement system produced by eliminatingthe carbon cloth 200 from the measurement system illustrated in FIG. 4.For these alloy plate coated materials 100, the contact resistancevalues between upper and lower copper electrodes 300 that sandwiched atest piece therebetween, were measured under a load of 1 MPa (10.2(kg/cm²)) using an ohm meter (manufactured by Hioki E.E. Corporation,MILLI-OHM HITESTER 3540). The measurement results are presented in Table1.

According to the results of Table 1, in Examples 3 and 5 in which analloy plate layer 20 having a molar ratio of M1 (Ni) to M2 (Pd) (Ni/Pd)of 0.005 to 0.5 was formed on a base material 10, the contact resistancehad a lower value compared to SUS316L (Comparative Example 2) that isused as a material for a conventional separator for a fuel cell or thelike, and excellent electrical conductivity was obtained. On the otherhand, according to the results of Table 1, in Comparative Example 3 inwhich the molar ratio of M1 (Ni) to M2 (Pd) (Ni/Pd) for the alloy platelayer 20 was not in the range of 0.005 to 0.5, the contact resistancevalue was slightly higher compared to Examples 3 and 5, andconsequently, slightly poor electrical conductivity was obtained.

Next, Examples of analyzing the surface state of the stainless steelmaterials and evaluating the plating properties and adhesiveness aredescribed below.

Example 6

First, a stainless steel material (SUS316L) was prepared as a basematerial 10. Subsequently, the base material 10 thus prepared wasimmersed in an aqueous solution of sulfuric acid having a sulfuric acidconcentration of 25 vol % under the conditions of a temperature of 70°C. and an immersion time of 5 seconds, and thereby a stainless steelsheet having a passivation film formed on the surface was obtained.

Example 7

A stainless steel sheet having a passivation film formed on the surfacewas obtained in the same manner as in Example 6, except that the basematerial 10 thus prepared was immersed in an aqueous solution ofsulfuric acid having a sulfuric acid concentration of 25 vol % under theconditions of a temperature of 70° C. and an immersion time of 10seconds.

Example 8

A stainless steel sheet having a passivation film formed on the surfacewas obtained in the same manner as in Example 6, except that the basematerial 10 thus prepared was immersed in an aqueous solution ofsulfuric acid having a sulfuric acid concentration of 25 vol % under theconditions of a temperature of 70° C. and an immersion time of 15seconds.

Example 9

A stainless steel sheet having a passivation film formed on the surfacewas obtained in the same manner as in Example 6, except that the basematerial 10 thus prepared was immersed in an aqueous solution ofsulfuric acid having a sulfuric acid concentration of 25 vol % under theconditions of a temperature of 70° C. and an immersion time of 20seconds.

Then, for each of Examples 6 to 9 of stainless steel sheets having suchpassivation films formed thereon, the amounts of Cr, O and Fe in at %were measured from 5 sites using a scan type Auger electron spectroscopyanalyzer (AES) (manufactured by JEOL, Ltd., product No.: JAMP-9500F),and the results thus obtained were averaged. Thereby, the Cr/O value (at% of Cr/at % of O) and the Cr/Fe value (at % of Cr/at % of Fe) weredetermined. The results are presented in Table 2.

Subsequently, for each of Examples 6 to 9 of the stainless steel sheetshaving passivation films formed thereon, a Ni—Pd—P alloy layer wasformed on the passivation film in the same manner as in Example 3 asdescribed above, and thus an alloy plate coated material 100 wasobtained.

Then, for the alloy plate coated materials 100 obtained as such, anevaluation of the plating properties of the Ni—Pd—P alloy layers wascarried out. Specifically, the surface of each of the alloy plate coatedmaterials 100 was analyzed using a fluorescent X-ray analyzer(manufactured by Rigaku Corporation, product No.: ZSX100e), and thepresence or absence of the Ni—Pd—P alloy was determined. In a case inwhich the Ni—Pd—P alloy was detected, it was considered that a Ni—Pd—Palloy layer was satisfactorily formed, and thus an evaluation of theplating properties was carried out. The results are presented in Table2. Consequently, in the alloy plate coated materials 100 of Examples 6to 9, the Ni—Pd—P alloy was detected from the surface, and it wasconfirmed that a Ni—Pd—P alloy layer was satisfactorily formed.

Furthermore, for the alloy plate coated materials 100 of Examples 6 to9, an evaluation of the adhesiveness of the Ni—Pd—P alloy layer wascarried out. Specifically, a peeling test was carried out by adhering anadhesive tape (manufactured by Nichiban Co., Ltd., NICETACK powerfultype) to the Ni—Pd—P alloy layer of each of the alloy plate coatedmaterials 100, and then detaching the adhesive tape. Thereafter, thedetachment state of the Ni—Pd—P alloy layer was observed, and in a casein which detachment was not recognized, it was considered that theadhesiveness of the Ni—Pd—P alloy layer was satisfactory. Thus, anevaluation of adhesiveness was carried out. The results are presented inTable 2. Consequently, for the alloy plate coated materials 100 ofExamples 6 to 9, detachment of the Ni—Pd—P alloy layer was notrecognized, and it was confirmed that the Ni—Pd—P alloy layer hadsatisfactory adhesiveness.

TABLE 2 Immersion Concentration Temperature time Passivation film NiPdPplate layer Kind of acid [vol %] [° C.] [sec] Cr/O value Cr/Fe valuePlating properties Adhesiveness Example 6 Sulfuric acid 25 70 5 0.19870.7918 good good Example 7 10 0.1833 0.6175 good good Example 8 150.1264 0.5631 good good Example 9 20 0.092 0.5577 good good

From the results of Table 2, in regard to Examples 6 to 9 in which apassivation film having a Cr/O value in the range of 0.09 to 0.20 and aCr/Fe value in the range of 0.55 to 0.80 at the surface as measured byan Auger electron spectroscopy analysis, was formed on a stainless steelsheet as the base material 10, it was confirmed that the Ni—Pd—P alloylayer formed on the passivation film had excellent plating propertiesand adhesiveness. Meanwhile, Table 2 shows results with a Cr/O value of0.092 to 0.1987 and a Cr/Fe value of 0.5577 to 0.7918 for thepassivation film of the stainless steel sheet. However, in considerationof the errors of the analysis results of an Auger electron spectroscopyanalysis, it is considered that when a passivation film having a Cr/Ovalue in the range of 0.09 to 0.20 and a Cr/Fe value in the range of0.55 to 0.80 at the surface as measured by an Auger electronspectroscopy analysis is formed on a stainless steel sheet, the Ni—Pd—Palloy layer formed on the passivation film has excellent platingproperties and adhesiveness.

-   100 . . . Alloy plate coated material-   10 . . . Base material-   20 . . . Alloy plate layer

1. An alloy plate coated material comprising: a base material; and analloy plate layer formed on the base material to constitute an outermostlayer and formed from a M1-M2-M3 alloy, wherein in the M1-M2-M3 alloy,M1 is at least one element selected from Ni, Fe, Co, Cu, Zn and Sn; M2is at least one element selected from Pd, Re, Pt, Rh, Ag and Ru; and M3is at least one element selected from P and B, and the alloy plate layerhas a molar ratio of M1 to M2 (M1/M2) of 0.005 to 0.5.
 2. The alloyplate coated material according to claim 1, wherein the alloy platelayer has a glass transition point.
 3. The alloy plate coated materialaccording to claim 1, wherein the alloy plate layer is amorphous-like.4. The alloy plate coated material according to claim 1, wherein inregard to the alloy plate layer, the diffraction profile analyzed by agrazing incidence X-ray diffraction method using an X-raydiffractometer, has a shape which has no sharp peaks originating fromcrystals containing at least one element selected from among M1, M2 andM3, and/or a shape which has a halo originating from an amorphousstructure.
 5. A method of producing an alloy plate coated material, themethod comprising: forming an alloy plate layer formed from a M1-M2-M3alloy by electroless plating, on a base material so as to constitute anoutermost layer, wherein in regard to the M1-M2-M3 alloy, M1 is at leastone element selected from Ni, Fe, Co, Cu, Zn and Sn; M2 is at least oneelement selected from Pd, Re, Pt, Rh, Ag and Ru; and M3 is at least oneelement selected from P and B, and the alloy plate layer has a molarratio of M1 to M2 (M1/M2) is 0.005 to 0.5.